Reservoir assembly

ABSTRACT

A reservoir assembly for use as a fluid storage component in systems for actuating hydraulically operated devices. An apertured diffuser is disposed within the reservoir for reducing the velocity of fluid returning to the reservoir without decreasing the rate of fluid flow. In one aspect of the invention, the reservoir assembly is made entirely of a noncorrosive material to prevent contamination of the hydraulic fluid. To this end, for example, the reservoir comprises a one piece, seamless plastic container, while the diffuser is likewise, for example, made of plastic material.

United States Patent Snyder RESERVOIR ASSEMBLY [72] Inventor: David M. Snyder, Muncie, Ind.

I [73] Assignee: Muncie Parts Mfg. Co., Inc.,' Muncie, Ind.

[22] Filed: Oct. 12, 1970 [21] Appl. No.: 79,792

52 U.S. Cl. ..137/590, 137/592, 220/86 51 1m. 01 ..FlSb 1/04 [58] Field or Search... 137/590, 592; 220/86; 303/85 9 [56] References Cited UNITED STATES PATENTS 3,198,376 8/1965 Ashley, Jr ..220 86 2,602,465 7/1952 Goehring ..137/592 x 3,330,439 7/1967 Moorman .....220/86 51 Aug. 8, 1972 2,896,862 7/l959 3,428,061 2/l969 Graham ..l37/592X Primary Examiner-William R. Cline Attomey-Hume, Clement, Hume & Lee

[57] ABSTRACT A reservoir assembly for use as a fluid storage component in systems for actuating hydraulically operated devices. An apertured diffuser is disposed within the reservoir for reducing the velocity of fluid returning to the reservoir without decreasing the rate of fluid flow. In one aspect of the invention, the reservoir assembly is made entirely of a non-corrosive material to prevent contamination of the hydraulic fluid. To this end, for example, the reservoir comprises a one piece, seamless plastic container, while the difiuser is likewise, for example, made of plastic material.

4 Claim, 3 Drawing Figures Bede .....137/592 x Patented Aug. 8, 1972 .JiZU nfor vfws.

i 60 P2 Z 45 RESERVOIR ASSEMBLY BACKGROUND OF THE INVENTION This invention relates to a reservoir assembly for storing fluid in a system for actuating hydraulically operated devices. More particularly, the present invendecreased without reducing the rate of fluid flow in gallons per minute.

Fluid handling and storage systems are known in the prior art which use conventional metal reservoirs as storage components for the hydraulic fluid. These metal reservoirs have welded seams which may or may not be uniform in bond, depending on the skill and attitude of the welder. Conventional reservoirs also are unable to prevent contamination of the fluid, which is the largest cause of failures in hydraulic systems. The types of contaminents usually found in a fabricated metal tank are welding slag, sand, rust, and excessive moisture. The particulate size of these contaminants is in the 100-200 micron range, which causes difficulty since high pressure hydraulic components cannot pass contaminants larger 1 than microns without eventually being destroyed.

It has also been found that conventional reservoir assemblies lack effective means to reduce the velocity, but not the flow rate, of the fluid returning to the reservoir. As a result, the high velocity of returning fluid weakens the conventional reservoir at its seams and eventually causes it to break open.

It is also not uncommon for the returning fluid to be blown through a breather cap and deposit a film of oil on the outside of the reservoir as well as on nearby equipment. Attempts to overcome this problem in the prior art have included the installation of baffle plates situated vertically in the reservoir, dividing it into two sections. This, however, functions more as an antisloshing device and has proven to be quite ineffective in controlling the velocity of the returning fluid. A second use of the baffle plate has been to place it in the reservoir a few inches above and across the return port.

fluid storage and handling system which is seamlessly constructed and has unifonn wall thickness, and which results in outstanding toughness and the elimination of weak areas and leaky seams.

Another object of my invention is to provide a reservoir assembly for a hydraulic fluid storage and handling system wherein the possibility of the reservoir assembly bursting under pressure is drastically reduced, if not eliminated altogether.

Other objects of my invention will become apparent from the specification which follows and from the drawing to which reference is now made.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 schematically illustrates the present invention installed in a vehicle with the reservoir component shown partly in section located rearwardly of the cab of the vehicle;

FIG. 2 is an enlarged view of the diffuser illustrated in the cut-away section of the reservoir of FIG. 1; and

FIG. 3 is a perspective view of the reservoir assembly of the present invention, partly cut away to show a preferred location for the diffuser located therein.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 discloses the reservoir assembly 10 of the present invention installed on a truck 12 as the storage component of a hydraulic system for supplying fluid under pressure to hydraulically actuated devices, such as a dump body (not shown) mounted on the rear portion of truck frame 14. The hydraulic system may also be used to supply fluid under pressure to additional fluid operated equipment associated with the vehicle, such as hoists, winches, lifts, etc.

Power for the hydraulic system is supplied by a power take-0E unit 16 which is driven by the truck engine, not shown. A driven output shaft 18 transfers power from power take-off unit 16 to drive shaft 20 through a universal connection 22. At the other end of drive shaft 20, a slip length universal joint 24 attaches However, this usage does not allow an even disposal of the fluid stream, thereby causing the formation of air bubbles and foam in the fluid which in turn, causes cavitation in hydraulic pumps.

SUMMARY OF THE INVENTION In the present invention, the possibility of the reservoir weakening at the seams and bursting open is drastically reduced, if not eliminated altogether.

It will be apparent from the foregoing that a primary I object of the present invention is to provide a reservoir drive shaft 20 to input shaft 26 of hydraulic pump 28. Hydraulic fluid is conveyed under pressure from pump 28 through conduit 30 to the dump body actuating mechanism, or to other hydraulically operated equipment associated with truck 12.

Hydraulic fluid for use in the above described system is stored in reservoir assembly 10 which comprises a reservoir 32 mounted by means of a platform 33 to truck frame 14. Straps 37 extend around the periphery of reservoir 32 and fasten the reservoir assembly 10 to platform 33 (FIG. 3). A breather cap 35 is provided on top of reservoir 32 to prevent build-up of pressure inside the reservoir. A port 34 is provided in the bottom of reservoir 32 and extends through platform 33. Conduit 36 is fastened at one end to vehicle frame 14 by means of clamp coupling or bracket 38, located on the underside of reservoir 32 and platform 33 directly adjacent port 34. The other end of conduit 36 is connected by an El joint 40 to conduit 30 at or near the point where conduit 30 is affixed to pump 28.

Pump 28 is adapted to pump hydraulic fluid stored in reservoir 32 through port 34 and conduit 36, and thence through conduit 30 to the hydraulically operated equipment associated with truck 12. Assuming such equipment comprises a conventional dump body, hydraulic fluid passing from pump 28 to conduit 30 will function to raise the dump body to an inclined position relative to the truck frame 14. When it is under pressure, dueto non-uniform seams, and walls of non-uniform thickness. Also, it is not uncommon for the fluid returning to an ordinary reservoir to blow thoughthe breather cap and distribute a film of oil over the outside of the reservoir and on nearby equipment.

The reservoir assembly disclosed herein overcomes the disadvantages mentioned above by providing a fluid storage component of uniform construction. The reservoir assembly also is able to withstand the higher stresses normally occassioned in the hydraulic systems found in modern vehicles by reducing the velocity of the fluid returning to the reservoir, without reducing the flo'w rate. To this end, a diverging device such as diffuser 42 is aflixed to the inside bottom portion of reservoir 32 directly adjacent port 34. Flange means 43 are provided adjacent the open end 46 of diffuser 42. Mounting holes 45 are provided in flange 43 by which means diffuser 42 may be securely fastenedto the inside bottom surface of reservoir 32 (FIG. 3). As shown in more detail in FIG. 2, diffuser 42 comprises a cylindrical body 44 having an open port 46 atone end and a capped or closed end 48. The cylindrical body 44 of thediffuser 42 includes apertures 50 located in staggered relationship throughout the entire surface area of the diffuser wall. As best illustrated in FIG. 1, the inside diameter of the diffuser 42 is larger than the inside diameter of conduit 36 and the diameter of port 34.

The flow path of fluid entering reservoir 32 from conduit '36 expands when itpasses port 34 due to the larger diameter of diffuser 42. The volumetric displacement and the quantity of open area in the diffuser wall provided by apertures 50, and the net head or pressure of the hydraulic fluid, are the parameters which detercontaminants such as welding slag, sand, rust, and moisture, and these contaminants maycause permanent damage to hydraulic components if they enter the fluid stream. The construction of the reservoir 32 and diffuser 42 of the present invention eliminates the problem of non-uniform seams and contaminants. In the preferred embodiment of my invention, the reservoir 32 is a rotationally molded, seamless, high density polyethylene vessel with wallsof uniform thickness. Being constructed of polyethylene, the reservoir 32 is free of the corrosion causing contaminants usually found in metal welded tanks, and removes the responsibility for providing a contaminant free tank from the mechanics installing the hydraulic system. The polyethylene material provides a tank which is tough, rigid, lightweight, abrasion resistant and corrosion free. Preferably, the diffuser 42 is also made from high density polyethylene to further reduce the possibility of foreign matter entering the hydraulic fluid stream.

In some installations, another parallel hydraulic system with apparatus identical to pump 28 and conduits 30 and 36 may be operational on the opposing side of the vehicle 12. It is within the scope of .the:

present invention to provide a reservoir 32 with two ports 34 and two diffusers 42 located on either side of the reservoir to cooperate with two conduits 36. I

The foregoing embodiment is exemplary of the .in-

' vention and may be used as a model for constructing mine the flow rate of the fluid stream, usually measured in gallons per minute. Due to the divergent character of "diffuser 42 relative to the size of conduit 36 and port 34, the velocity of the fluid stream entering reservoir 32 is reduced without a corresponding reduction in the fluid flow rate in gallons per minute. When the fluid stream is slowed down, a portion of the kinetic energy in the stream is converted to potential, or pressure energy. The pressure of the fluid in the diffuser 42, therefore, is greater than the pressure downstream in conduit 36. This pressure is distributed by the diffuser 42, wherein the staggered placement of the apertures allows a uniform dispersal of the fluid stream in reservoir 32.

As stated previously, the conventional hydraulic system reservoir is a welded metal pressure vessel which has varying stress capabilities depending on the quality of the welded seam. Also, a metal tank contains the invention, however, many variations may'be made without departing from the spirit and scope of the invention as defined in the following claims.

I claim:

1. A reservoir assembly for a hydraulic system having a high-pressure return flow from a hydraulically activated device in the hydraulic system, said reservoir assembly comprising:

a seamless reservoir for storing hydraulic fluid, said seamless reservoir being formed from a non-corrosive material to prevent said seamless reservoir from producing contaminant particles tov contaminate the hydraulic fluid stored in said seamless reservoir and having port means for passing hydraulic fluid to and fromsaid seamless reservoir;

cylindrical diffuser means positioned over said port means in said reservoir, said diffuser means having a plurality of apertures therein, the number of said apertures being sufficient to reduce the velocity of hydraulic fluid flow into said seamless reservoir without decreasing the rate of flow of hydraulic fluid into said seamless reservoir; and

means for coupling said reservoir to said hydraulically activated device to permit flow of hydraulic fluid to and from said hydraulically activated device. a

2. The reservoir assembly of claim 1 wherein said diffuser means is fonned from a non-corrosive material to prevent said diffuser means from producing contaminant particles to contaminate the hydraulic fluid stored in said seamless reservoir.

3.. The reservoir assembly of claim 2 wherein said seamless reservoir is rotationally molded from high density polyethylene.

4. The reservoir of claim 3 wherein said diffuser means is formed from high density polyethylene. 

1. A reservoir assembly for a hydraulic system having a highpressure return flow from a hydraulically activated device in the hydraulic system, said reservoir assembly comprising: a seamless reservoir for storing hydraulic fluid, said seamless reservoir being formed from a non-corrosive material to prevent said seamless reservoir from producing contaminant particles to contaminate the hydraulic fluid stored in said seamless reservoir and having port means for passing hydraulic fluid to and from said seamless reservoir; cylindrical diffuser means positioned over said port means in said reservoir, said diffuser means having a plurality of apertures therein, the number of said apertures being sufficient to reduce the velocity of hydraulic fluid flow into said seamless reservoir without decreasing the rate of flow of hydraulic fluid into said seamless reservoir; and means for coupling said reservoir to said hydraulically activated device to permit flow of hydraulic fluid to and from said hydraulically activated device.
 2. The reservoir assembly of claim 1 wherein said diffuser means is formed from a non-corrosive material to prevent said diffuser means from producing contaminant particles to contaminate the hydraulic fluid stored in said seamless reservoir.
 3. The reservoir assembly of claim 2 wherein said seamless reservoir is rotationally molded from high density polyethylene.
 4. The reservoir of claim 3 wherein said diffuser means is formed from high density polyethylene. 